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package org.kedacom.comet.util;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

/**
 *
 * @author Bill
 */
public class CharacterEncodingFilter implements Filter {
     /**
     *
     * 对 HttpServletRequestWrapper 进行扩充, 不影响原来的功能并能提供所有的 HttpServletRequest
     * 接口中的功能. 它可以统一的对 Tomcat 默认设置下的中文问题进行解决而只需要用新的 Request 对象替换页面中的
     * request 对象即可.
     */
    protected String encoding = null;
    protected FilterConfig filterConfig = null;
    //protected boolean ignore = true;

    public void destroy() {
        this.encoding = null;
        this.filterConfig = null;
    }

    class Request extends HttpServletRequestWrapper {

        public Request(HttpServletRequest request) {
            super(request);
        }
        /**
         * 转换由表单读取的数据的内码.
         * 从 ISO 字符转到 utf-8(或gbk).
         */
        public String toChi(String input) {
            try {

              byte[] bytes = input.getBytes("ISO-8859-1");
              return new String(bytes, encoding);
            }
            catch (Exception ex) {
            }
            return null;
        }

        /**
         * Return the HttpServletRequest holded by this object.
         */
        private HttpServletRequest getHttpServletRequest()
        {
            return (HttpServletRequest)super.getRequest();
        }

        /**
         * 读取参数 -- 修正了中文问题.
         */
        public String getParameter(String name)
        {
            return toChi(getHttpServletRequest().getParameter(name));
        }

        /**
         * 读取参数列表 - 修正了中文问题.
         */
        public String[] getParameterValues(String name)
        {
              String values[] = getHttpServletRequest().getParameterValues(name);
              if (values != null) {
                for (int i = 0; i < values.length; i++) {
                  values[i] = toChi(values[i]);
                }
              }
              return values;
        }
    }
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
        throws IOException, ServletException {

    	System.out.println("字符过滤");
       // if (ignore || (request.getCharacterEncoding() == null)) {
       //     String encoding = selectEncoding(request);
            /*if (encoding != null)
                request.setCharacterEncoding(encoding);*/
       // }
        HttpServletRequest httpreq = (HttpServletRequest)request;
        if(httpreq.getMethod().equals("POST")) {
            request.setCharacterEncoding(encoding);
        } else {
            request = new Request(httpreq);
        }

    // Pass control on to the next filter
        chain.doFilter(request, response);

    }


    /**
     * Place this filter into service.
     *
     * @param filterConfig The filter configuration object
     */
    public void init(FilterConfig filterConfig) throws ServletException {

    this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");


    }

}

